In fuel injection pumps of the type having reciprocating pumping plungers, the fuel charge which can be delivered by the pump is frequently controlled by limiting the outward fuel intake stroke of the pumping plungers to provide a relatively large fuel charge during starting and a lower fuel charge limit during normal engine operation which avoids incomplete combustion and resulting pollution. A plunger stroke limit mechanism providing such fuel charge control is disclosed in the pending U.S. application Ser. No. 859,847, now U.S. Pat. No. 4,225,291 of the common assignee hereof, of Gerald R. Bouwkamp, filed Dec. 12, 1977, and entitled "Fuel Injection Pump and Plunger Control Means Therefor". However, it has been found that normal wear of the parts of such a mechanism will result in an undesirable increase in the plunger intake stroke limit to permit excess fuel and resulting incomplete and inefficient combustion and pollution during full load engine operation.
It is, therefore, a principal object of the present invention to provide a new and improved fuel injection pump stroke limit mechanism of the type described in U.S. application Ser. No. 859,847 for establishing a plunger intake stroke limit which will not substantially increase during an extended operating period of the pump.
It is another object of the present invention to provide a new and improved fuel injection pump stroke limit mechanism of the type described which provides automatic wear compensation for preventing wear from causing increase in the plunger stroke limit.
It is still another object of the present invention to provide an improved stroke limit mechanism of the type described for setting a predetermined plunger stroke limit which remains within a close tolerance over a substantial useful operating period of the pump.
A still further object of the present invention is to provide a new and improved plunger stroke limit mechanism which can be economically fabricated and assembled and which will operate effectively over a long period of use without adjustment.
Other objects will be in part obvious and in part pointed out more in detail hereinafter.
A better understanding of the invention will be obtained from the following detailed description and the accompanying drawings.